with dan abrams. &#9834; Reporter: The question at this summer's trial of george zimmerman -- was it murder, manslaughter, or self-defense when he shot and killed trayvon martin? If a black man went into a white neighborhood and gunne down a 17-year-old boy, all hell would let loose. Reporter: What everyone wanted to know was, who was screaming for help on those neighbors 911 calls? Help! There's just someone screaming outside. Help! Do you think he's yelling help? Yes. Reporter: And then there was the prosecution's so-called star witness -- the friend of martin's who was on the phone with him minutes before he died who suddenly found herself on the hot seat. That's real retarded, sir. I think she didn't give a fig about the jury or anybody else and that they picked up on that. Reporter: In the end, it may have been this photo of the back of zimmerman's head as well the testimony of a neighbor that convinced jurors. I could tell that the person on the bottom had a lighter skin color. Zimmerman started the whole thing. You can start it. And then you end up on the bottom. And you're supposedly getting your head bashed into the round, even if you deserve it. Got a tough case. Okay, let's -- let's think this through. Trayvon martin dead, zimmerman two band-aids. Hmm. Doesn't really sound like self-defenme. The band-aid standard isn't the legal standard. It is to me in this case. The jury has reached a verdict. We, the jury, find george zimmerman not guilty. I thought we were going to get some kind of justice. We as the kbhunt knew it, we said he would be acquitted. Reporter: The verdict reverberated all over the country, inspiring 4.5 million tweets the first day. Even the president spoke out. Trayvon martin could have been me 35 years ago. Reporter: The only juror of color spoke to abc about the painful decision. I stand by the decision because of the law. But if I stand by the decision because of my heart, he would have been guilty. It was a total copout. Pass the buck. Blame it on the law. You know what? That horrible thing, the law. Yeah, the law. Why listen to the law -- they blamed it on the law. Reporter: In the months since zimmerman's acquittal, he has been arrested twice after domestic disputes with both his estranged wife and a girlfriend. He just broke my glass table. You broke my sunglasses an you put your gun in my fricken' face. The minute he pulled that shotgun on his girlfriend, i went, I hope that jury's happy. Reporter: Another legal issue that divided the nation this year? Gay marriage. Two landmark supreme court RULINGS CAME DOWN ON JUNE 26th. In one, the court refused to reinstate california ballot initiative prop 8, which banned gay marriages in that state. Will you please marry me? Reporter: But in the other, much more sweeping ruling, justices struck down part of the defense of marriage act, allowing legally married homosexual couples the same benefits as straight ones. We won everything we asked and hoped for. Reporter: The case was brought by 84-year-old plaintiff and wife, edie windsor, whose wife and partner of 40 years died in 2009. She was hit with $363,000 in estate taxes -- taxes no heterosexual widow would have to pay. Reporter: Celebrations erupted when news broke of the rulings. For others it was a dark day. It's a sad day when unelected judges change the definition of marriage and turn their backs on the will of voters. Reporter: Now 16 states and the district of columbia have legalized gay marriage. It's all anybody is taking about in this town. Reporter: And while memorized us. Wall to wall coverages. How does she get to tweet. Countless parodies. I don't remember. It sounded fishy to me. You and the jury. Reporter: Even a made for tv movie. I'm done talking. She is a hotty. Let's be honest. She has a killer body, literally. Reporter: Accused of murdering her ex-boyfriend travis alexander back in 2008, remember that bizarre interrogation footage. No jury is going to convict me. Why not? Because I'm innocent. Reporter: After four and a half years in jail, areas the one time blonde bomb shell transformed herself for the eight-month trial. She changed her hair color. She was a fantastic villain in the thing. She was absolutely stair you straight in the eye and lie until the cows came home. He attacked me. Reporter: What about the 27 stab wounds that followed? I don't remember stack. Reporter:18 days on the stand. With her sex life taking center stage. Do you like dressing up a horny little schoolgirl for lack of a better term? Right? If I had to look at jodi arias naked shots one more time, jodi arias did not help herself at all. She made the jury loathe her. We the jury do find the defendant guilty. Reporter: Even after the verdict, jodi arias was still talking. So you really are never going to tell the truth about what went down in that bathroom? I don't know what you mean by that, because I told the truth. Okay. I didn't know that you were a hater when you came to interview me. I'm not a hater. Reporter: What do you think makes jodi arias tick? You invite the devil into your mind. You invite him to a tea party, honey? He will stay for dinner. So I don't want to think about what makes jodi arias tick. Announcer: Next -- katie

This transcript has been automatically generated and may not be 100% accurate.